Communications systems, such as, for example, those used in telephony applications often require the transfer of control, messaging and payload data between components via a single serial link. A modular communications system which may utilize such a serial link is disclosed in co-pending U.S. patent application Ser. No. 08/721,095, still pending, the contents of which are incorporated by reference, herein.
If, as in the disclosed system, the payload data may further be transferred from and to a host systems, the serial link should accommodate the transfer of such data without manipulating the format of the payload data used by the host system. Moreover, the clock of the communications system and the serial link should be synchronized with the clock of the host system and the clock of the interface to the host system. Further, the bandwidth of the serial link should be sufficient to meet system requirements, but should also be flexible in order to support a plurality of applications. Finally, in addition to carrying payload data the link should carry low level control data between the components, and potentially high level control or messaging data and framing data.
The present invention seeks to meet some of the above requirements.